README: update instructions regarding git

github is removing support for git:// protocol, we should use https://
now

README.md

@@ -9,7 +9,7 @@ The documentation can be found on [https://jio.nexedi.com/](https://jio.nexedi.c
 ### jIO Quickstart
     git clone https://lab.nexedi.com/nexedi/jio.git
     cd jio.git
-    npm install jslint@0.9.2 jison@0.4.16 git://github.com/qunitjs/node-qunit.git#v0.9.3 sinon@1.7.3
+    npm install jslint@0.9.2 jison@0.4.16 https://github.com/qunitjs/node-qunit.git#v0.9.3 sinon@1.7.3
     make